Sprint is slowly continuing its rollout of its heavily customized Wi-Fi calling solution currently exclusive to its Android device lineup by pushing out the update to the Sprint Spark compatible version of the Samsung Galaxy S4. The following is being touted by Sprint with the addition of Wi-Fi Calling and is promising more phone compatibility during the year.

Easy setup: Once activated, everything is seamless and happens in the background

Unlimited voice calling and messaging on Wi-Fi: All domestic calling and messaging is FREE (standard CDMA international rates apply for international calls)

Once the download is complete, you will be prompted to install the update. Installation will take a few minutes during which the device will be disabled. Once installation is completed, the device will be ready for use and Wi-Fi Calling can be activated by going to your Apps folder and selecting the Wi-Fi Calling icon.

As previously reported, Sprint’s implementation of Wi-Fi calling will allow for unlimited voice and messaging over any open Wi-Fi network in the US, although unlike T-Mobile’s implementation, it will not be free when used internationally, with voice calls being charged at their current international rates when placed internationally. In an ironic twist, Sprint has also discontinued one of the main smartphone models that led the rollout of its Wi-Fi Calling service in the Samsung Galaxy Mega 6.3.